Abby L. West

DNase 1 Retains Endodeoxyribonuclease Activity Following Gold Nanocluster Synthesis

Here we present the synthesis of the enzyme DNase 1 stabilized gold nanoclusters (DNase 1:AuNCs) with core size consisting of either 8 or 25 atoms. The DNase 1:Au8NCs exhibit blue fluorescence whereas the DNase 1:Au25NCs are red emitting. In addition to the intense fluorescence emission, the synthesized DNase 1:AuNC hybrid retains the native functionality of the protein, allowing simultaneous detection and digestion of DNA with a detection limit of 2 μg/mL. The DNase 1:AuNCs could be conveniently employed as efficient and fast sensors to augment the current time-consuming DNA contamination analysis techniques.

In situ Synthesis of Fluorescent Gold Nanoclusters by Nontumorigenic Microglial Cells.

To date, the directed in situ synthesis of fluorescent gold nanoclusters (AuNCs) has only been demonstrated in cancerous cells, with the theorized synthesis mechanism prohibiting AuNC formation in nontumorigenic cell lines. This limitation hinders potential biostabilized AuNC-based technology in healthy cells involving both chemical and mechanical analysis, such as the direct sensing of protein function and the elucidation of local mechanical environments. Thus, new synthesis strategies are required to expand the application space of AuNCs beyond cancer-focused cellular studies. In this contribution, we have developed the methodology and demonstrated the direct in situ synthesis of AuNCs in the nontumorigenic neuronal microglial line, C8B4. The as-synthesized AuNCs form in situ and are stabilized by cellular proteins. The clusters exhibit bright green fluorescence and demonstrate low (<10%) toxicity. Interestingly, elevated ROS levels were not required for the in situ formation of AuNCs, although intracellular reductants such as glutamate were required for the synthesis of AuNCs in C8B4 cells. To our knowledge, this is the first-ever demonstration of AuNC synthesis in nontumorigenic cells and, as such, it considerably expands the application space of biostabilized fluorescent AuNCs.

Gold Nanocluster DNase 1 Hybrid Materials: An Efficient Method for DNA Contamination Sensing.

Protein-encapsulated gold nanocluster (P-AuNC) synthesis was first demonstrated in 2009 [1]. Initially, these P-AuNCs were used as cellular imaging agents as the protein shell surrounding the AuNC made them highly biocompatible. However, recent studies have begun to show that these stabilizing proteins may also retain native biological function, thus giving a dual functionality to these hybrid molecules. Here, we present the synthesis of DNase 1 stabilized AuNCs (DNase 1:AuNCs) with core sizes consisting of either eight or 25 atoms. The DNase 1:Au8NCs exhibit blue fluorescence, whereas the DNase 1:Au25NCs are red emitting. Moreover, in addition to the intense fluorescence emission, the synthesized DNase 1:AuNC hybrids retain the native functionality of the protein, allowing simultaneous detection and digestion of DNA with a detection limit of 2 mg/mL (Figure 1). The DNase 1:AuNCs could be conveniently employed as efficient and fast sensors to augment the current inefficient and time-consuming DNA contamination analysis techniques.

Gold nanocluster-DNase 1 hybrid materials for DNA contamination sensing

Protein encapsulated gold nanocluster (P-AuNC) synthesis was first demonstrated in 2009.[1] Initially these P-AuNCs were used as cellular imaging agents as the protein shell surrounding the AuNC made them highly biocompatible. However, recent studies have begun to show that these stabilizing proteins may also retain native biological function thus giving a dual functionality to these hybrid molecules. Here we present the synthesis of DNase 1 stabilized gold nanoclusters (DNase 1:AuNCs) with core sizes consisting either 8 or 25 atoms. The DNase 1:Au8NCs exhibit blue fluorescence whereas the DNase 1:Au25NCs are red emitting. Moreover, in addition to the intense fluorescence emission; the synthesized DNase 1:AuNC hybrid retain the native functionality of the protein, allowing simultaneous detection and digestion of DNA with a detection limit of 2 μg/mL (Scheme 1). The DNase 1:AuNCs could be conveniently employed as efficient and fast sensors to augment the current inefficient and time consuming DNA contamination analysis techniques.